<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE html><html xmlns="http://www.w3.org/1999/xhtml">
  <head>
    <title>glReadPixels - OpenGL 4 Reference Pages</title>
    <link rel="stylesheet" type="text/css" href="opengl-man.css"/>
    <meta name="generator" content="DocBook XSL Stylesheets V1.78.1"/>
    <script type="text/x-mathjax-config">
            MathJax.Hub.Config({
                MathML: {
                    extensions: ["content-mathml.js"]
                },
                tex2jax: {
                    inlineMath: [['$','$'], ['\\(','\\)']]
                }
            });
        </script>
    <script type="text/javascript" src="https://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML"/>
  </head>
  <body>
    <header/>
    <div class="refentry" id="glReadPixels">
      <div class="titlepage"/>
      <div class="refnamediv">
        <h2>Name</h2>
        <p>glReadPixels, glReadnPixels — read a block of pixels from the frame buffer</p>
      </div>
      <div class="refsynopsisdiv">
        <h2>C Specification</h2>
        <div class="funcsynopsis">
          <table style="border: 0; cellspacing: 0; cellpadding: 0;" class="funcprototype-table">
            <tr>
              <td>
                <code class="funcdef">void <strong class="fsfunc">glReadPixels</strong>(</code>
              </td>
              <td>GLint <var class="pdparam">x</var>, </td>
            </tr>
            <tr>
              <td> </td>
              <td>GLint <var class="pdparam">y</var>, </td>
            </tr>
            <tr>
              <td> </td>
              <td>GLsizei <var class="pdparam">width</var>, </td>
            </tr>
            <tr>
              <td> </td>
              <td>GLsizei <var class="pdparam">height</var>, </td>
            </tr>
            <tr>
              <td> </td>
              <td>GLenum <var class="pdparam">format</var>, </td>
            </tr>
            <tr>
              <td> </td>
              <td>GLenum <var class="pdparam">type</var>, </td>
            </tr>
            <tr>
              <td> </td>
              <td>GLvoid * <var class="pdparam">data</var><code>)</code>;</td>
            </tr>
          </table>
          <div class="funcprototype-spacer"> </div>
          <table style="border: 0; cellspacing: 0; cellpadding: 0;" class="funcprototype-table">
            <tr>
              <td>
                <code class="funcdef">void <strong class="fsfunc">glReadnPixels</strong>(</code>
              </td>
              <td>GLint <var class="pdparam">x</var>, </td>
            </tr>
            <tr>
              <td> </td>
              <td>GLint <var class="pdparam">y</var>, </td>
            </tr>
            <tr>
              <td> </td>
              <td>GLsizei <var class="pdparam">width</var>, </td>
            </tr>
            <tr>
              <td> </td>
              <td>GLsizei <var class="pdparam">height</var>, </td>
            </tr>
            <tr>
              <td> </td>
              <td>GLenum <var class="pdparam">format</var>, </td>
            </tr>
            <tr>
              <td> </td>
              <td>GLenum <var class="pdparam">type</var>, </td>
            </tr>
            <tr>
              <td> </td>
              <td>GLsizei <var class="pdparam">bufSize</var>, </td>
            </tr>
            <tr>
              <td> </td>
              <td>void *<var class="pdparam">data</var><code>)</code>;</td>
            </tr>
          </table>
          <div class="funcprototype-spacer"> </div>
        </div>
      </div>
      <div class="refsect1" id="parameters">
        <h2>Parameters</h2>
        <div class="variablelist">
          <dl class="variablelist">
            <dt>
              <span class="term"><em class="parameter"><code>x</code></em>, </span>
              <span class="term">
                <em class="parameter">
                  <code>y</code>
                </em>
              </span>
            </dt>
            <dd>
              <p>Specify the window coordinates of the first pixel that is read
          from the frame buffer. This location is the lower left corner of a
          rectangular block of pixels.</p>
            </dd>
            <dt>
              <span class="term"><em class="parameter"><code>width</code></em>, </span>
              <span class="term">
                <em class="parameter">
                  <code>height</code>
                </em>
              </span>
            </dt>
            <dd>
              <p>Specify the dimensions of the pixel rectangle.
          <em class="parameter"><code>width</code></em> and <em class="parameter"><code>height</code></em> of
          one correspond to a single pixel.</p>
            </dd>
            <dt>
              <span class="term">
                <em class="parameter">
                  <code>format</code>
                </em>
              </span>
            </dt>
            <dd>
              <p>Specifies the format of the pixel data. The following symbolic
          values are accepted: <code class="constant">GL_STENCIL_INDEX</code>,
          <code class="constant">GL_DEPTH_COMPONENT</code>,
          <code class="constant">GL_DEPTH_STENCIL</code>, <code class="constant">GL_RED</code>,
          <code class="constant">GL_GREEN</code>, <code class="constant">GL_BLUE</code>,
          <code class="constant">GL_RGB</code>, <code class="constant">GL_BGR</code>,
          <code class="constant">GL_RGBA</code>, and
          <code class="constant">GL_BGRA</code>.</p>
            </dd>
            <dt>
              <span class="term">
                <em class="parameter">
                  <code>type</code>
                </em>
              </span>
            </dt>
            <dd>
              <p>Specifies the data type of the pixel data. Must be one of
          <code class="constant">GL_UNSIGNED_BYTE</code>, <code class="constant">GL_BYTE</code>,
          <code class="constant">GL_UNSIGNED_SHORT</code>,
          <code class="constant">GL_SHORT</code>, <code class="constant">GL_UNSIGNED_INT</code>,
          <code class="constant">GL_INT</code>, <code class="constant">GL_HALF_FLOAT</code>,
          <code class="constant">GL_FLOAT</code>,
          <code class="constant">GL_UNSIGNED_BYTE_3_3_2</code>,
          <code class="constant">GL_UNSIGNED_BYTE_2_3_3_REV</code>,
          <code class="constant">GL_UNSIGNED_SHORT_5_6_5</code>,
          <code class="constant">GL_UNSIGNED_SHORT_5_6_5_REV</code>,
          <code class="constant">GL_UNSIGNED_SHORT_4_4_4_4</code>,
          <code class="constant">GL_UNSIGNED_SHORT_4_4_4_4_REV</code>,
          <code class="constant">GL_UNSIGNED_SHORT_5_5_5_1</code>,
          <code class="constant">GL_UNSIGNED_SHORT_1_5_5_5_REV</code>,
          <code class="constant">GL_UNSIGNED_INT_8_8_8_8</code>,
          <code class="constant">GL_UNSIGNED_INT_8_8_8_8_REV</code>,
          <code class="constant">GL_UNSIGNED_INT_10_10_10_2</code>,
          <code class="constant">GL_UNSIGNED_INT_2_10_10_10_REV</code>,
          <code class="constant">GL_UNSIGNED_INT_24_8</code>,
          <code class="constant">GL_UNSIGNED_INT_10F_11F_11F_REV</code>,
          <code class="constant">GL_UNSIGNED_INT_5_9_9_9_REV</code>, or
          <code class="constant">GL_FLOAT_32_UNSIGNED_INT_24_8_REV</code>.</p>
            </dd>
            <dt>
              <span class="term">
                <em class="parameter">
                  <code>bufSize</code>
                </em>
              </span>
            </dt>
            <dd>
              <p>Specifies the size of the buffer <em class="parameter"><code>data</code></em>
          for <code class="function">glReadnPixels</code> function.</p>
            </dd>
            <dt>
              <span class="term">
                <em class="parameter">
                  <code>data</code>
                </em>
              </span>
            </dt>
            <dd>
              <p>Returns the pixel data.</p>
            </dd>
          </dl>
        </div>
      </div>
      <div class="refsect1" id="description">
        <h2>Description</h2>
        <p><code class="function">glReadPixels</code> and
    <code class="function">glReadnPixels</code> return pixel data from the frame
    buffer, starting with the pixel whose lower left corner is at location
    (<em class="parameter"><code>x</code></em>, <em class="parameter"><code>y</code></em>), into client memory
    starting at location <em class="parameter"><code>data</code></em>. Several parameters
    control the processing of the pixel data before it is placed into client
    memory. These parameters are set with
    <a class="citerefentry" href="glPixelStore.xhtml"><span class="citerefentry"><span class="refentrytitle">glPixelStore</span></span></a>.
    This reference page describes the effects on
    <code class="function">glReadPixels</code> and <code class="function">glReadnPixels</code>
    of most, but not all of the parameters specified by these three
    commands.</p>
        <p>If a non-zero named buffer object is bound to the
    <code class="constant">GL_PIXEL_PACK_BUFFER</code> target (see
    <a class="citerefentry" href="glBindBuffer.xhtml"><span class="citerefentry"><span class="refentrytitle">glBindBuffer</span></span></a>)
    while a block of pixels is requested, <em class="parameter"><code>data</code></em> is
    treated as a byte offset into the buffer object's data store rather than
    a pointer to client memory.</p>
        <p><code class="function">glReadPixels</code> and
    <code class="function">glReadnPixels</code> return values from each pixel with
    lower left corner at <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
                
                <mml:mfenced open="(" close=")">
                    <mml:mrow>
                        <mml:mi mathvariant="italic">x</mml:mi>
                        <mml:mo>+</mml:mo>
                        <mml:mi mathvariant="italic">i</mml:mi>
                    </mml:mrow>
                    <mml:mrow>
                        <mml:mi mathvariant="italic">y</mml:mi>
                        <mml:mo>+</mml:mo>
                        <mml:mi mathvariant="italic">j</mml:mi>
                    </mml:mrow>
                </mml:mfenced>
            </mml:math>
            for
            <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
                
                <mml:mrow>
                    <mml:mn>0</mml:mn>
                    <mml:mo>&lt;=</mml:mo>
                    <mml:mi mathvariant="italic">i</mml:mi>
                    <mml:mo>&lt;</mml:mo>
                    <mml:mi mathvariant="italic">width</mml:mi>
                </mml:mrow>
            </mml:math>
            and
            <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
                
                <mml:mrow>
                    <mml:mn>0</mml:mn>
                    <mml:mo>&lt;=</mml:mo>
                    <mml:mi mathvariant="italic">j</mml:mi>
                    <mml:mo>&lt;</mml:mo>
                    <mml:mi mathvariant="italic">height</mml:mi>
                </mml:mrow>
            </mml:math>.
            This pixel is said to be the
            <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">i</mml:mi></mml:math>th
            pixel in the
            <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">j</mml:mi></mml:math>th
            row.
            Pixels are returned in row order from the lowest to the highest row,
            left to right in each row.
        </p>
        <p>
            <em class="parameter"><code>format</code></em> specifies the format for the returned pixel values;
            accepted values are:
        </p>
        <div class="variablelist">
          <dl class="variablelist">
            <dt>
              <span class="term">
                <code class="constant">GL_STENCIL_INDEX</code>
              </span>
            </dt>
            <dd>
              <p>
                        Stencil values are read from the stencil buffer.
                    </p>
            </dd>
            <dt>
              <span class="term">
                <code class="constant">GL_DEPTH_COMPONENT</code>
              </span>
            </dt>
            <dd>
              <p>
                        Depth values are read from the depth buffer.
                        Each component is converted to floating point such that the minimum depth
                        value maps to 0 and the maximum value maps to 1.
                        Each component is clamped to the range
                        <math overflow="scroll">
                            
                            <mfenced open="[" close="]">
                                <mn>0</mn>
                                <mn>1</mn>
                            </mfenced>
                        </math>.
                    </p>
            </dd>
            <dt>
              <span class="term">
                <code class="constant">GL_DEPTH_STENCIL</code>
              </span>
            </dt>
            <dd>
              <p>
                        Values are taken from both the depth and stencil buffers. The <em class="parameter"><code>type</code></em> parameter
                        must be <code class="constant">GL_UNSIGNED_INT_24_8</code> or <code class="constant">GL_FLOAT_32_UNSIGNED_INT_24_8_REV</code>.
                    </p>
            </dd>
            <dt>
              <span class="term"><code class="constant">GL_RED</code>,
                      <code class="constant">GL_GREEN</code>,
                      <code class="constant">GL_BLUE</code>,
                      <code class="constant">GL_RGB</code>,
                      <code class="constant">GL_BGR</code>,
                      <code class="constant">GL_RGBA</code>,
                      <code class="constant">GL_BGRA</code></span>
            </dt>
            <dd>
              <p>Color values are taken from the color buffer.</p>
            </dd>
          </dl>
        </div>
        <p>
            Finally, the indices or components
            are converted to the proper format,
            as specified by <em class="parameter"><code>type</code></em>.
            If <em class="parameter"><code>format</code></em> is <code class="constant">GL_STENCIL_INDEX</code>
            and <em class="parameter"><code>type</code></em> is not <code class="constant">GL_FLOAT</code>,
            each index is masked with the mask value given in the following table.
            If <em class="parameter"><code>type</code></em> is <code class="constant">GL_FLOAT</code>, then each integer index is converted to
            single-precision floating-point format.
        </p>
        <p>
            If <em class="parameter"><code>format</code></em> is
            <code class="constant">GL_RED</code>,
            <code class="constant">GL_GREEN</code>,
            <code class="constant">GL_BLUE</code>,
            <code class="constant">GL_RGB</code>,
            <code class="constant">GL_BGR</code>,
            <code class="constant">GL_RGBA</code>, or
            <code class="constant">GL_BGRA</code> and <em class="parameter"><code>type</code></em> is not <code class="constant">GL_FLOAT</code>,
            each component is multiplied by the multiplier shown in the following table.
            If type is <code class="constant">GL_FLOAT</code>, then each component is passed as is
            (or converted to the client's single-precision floating-point format if
            it is different from the one used by the GL).
        </p>
        <p>
        </p>
        <div class="informaltable">
          <table style="border-collapse: collapse; border-top: 2px solid ; border-bottom: 2px solid ; border-left: 2px solid ; border-right: 2px solid ; ">
            <colgroup>
              <col style="text-align: left; "/>
              <col style="text-align: center; "/>
              <col style="text-align: center; "/>
            </colgroup>
            <thead>
              <tr>
                <th style="text-align: left; border-right: 2px solid ; border-bottom: 2px solid ; ">
                            <em class="parameter"><code>type</code></em>
                        </th>
                <th style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
                            <span class="bold"><strong> Index Mask </strong></span>
                        </th>
                <th style="text-align: center; border-bottom: 2px solid ; ">
                            <span class="bold"><strong> Component Conversion </strong></span>
                        </th>
              </tr>
            </thead>
            <tbody>
              <tr>
                <td style="text-align: left; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <code class="constant">GL_UNSIGNED_BYTE</code>
                        </td>
                <td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <math overflow="scroll">
                            
                            <mrow>
                                <msup><mn>2</mn>
                                <mn>8</mn>
                                </msup>
                                <mo>-</mo>
                                <mn>1</mn>
                            </mrow>
                        </math>
                        </td>
                <td style="text-align: center; border-bottom: 2px solid ; ">
                        <math overflow="scroll">
                            
                            <mrow>
                                <mfenced open="(" close=")">
                                    <mrow>
                                        <msup><mn>2</mn>
                                        <mn>8</mn>
                                        </msup>
                                        <mo>-</mo>
                                        <mn>1</mn>
                                    </mrow>
                                </mfenced>
                                <mo>⁢</mo>
                                <mi mathvariant="italic">c</mi>
                            </mrow>
                        </math>
                        </td>
              </tr>
              <tr>
                <td style="text-align: left; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <code class="constant">GL_BYTE</code>
                        </td>
                <td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <math overflow="scroll">
                            
                            <mrow>
                                <msup><mn>2</mn>
                                <mn>7</mn>
                                </msup>
                                <mo>-</mo>
                                <mn>1</mn>
                            </mrow>
                        </math>
                        </td>
                <td style="text-align: center; border-bottom: 2px solid ; ">
                        <math overflow="scroll">
                            
                            <mfrac>
                                <mfenced open="" close="">
                                    <mrow>
                                        <mfenced open="(" close=")">
                                            <mrow>
                                                <msup><mn>2</mn>
                                                <mn>8</mn>
                                                </msup>
                                                <mo>-</mo>
                                                <mn>1</mn>
                                            </mrow>
                                        </mfenced>
                                        <mo>⁢</mo>
                                        <mi mathvariant="italic">c</mi>
                                        <mo>-</mo>
                                        <mn>1</mn>
                                    </mrow>
                                </mfenced>
                                <mn>2</mn>
                            </mfrac>
                        </math>
                        </td>
              </tr>
              <tr>
                <td style="text-align: left; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <code class="constant">GL_UNSIGNED_SHORT</code>
                        </td>
                <td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <math overflow="scroll">
                            
                            <mrow>
                                <msup><mn>2</mn>
                                <mn>16</mn>
                                </msup>
                                <mo>-</mo>
                                <mn>1</mn>
                            </mrow>
                        </math>
                        </td>
                <td style="text-align: center; border-bottom: 2px solid ; ">
                        <math overflow="scroll">
                            
                            <mrow>
                                <mfenced open="(" close=")">
                                    <mrow>
                                        <msup><mn>2</mn>
                                        <mn>16</mn>
                                        </msup>
                                        <mo>-</mo>
                                        <mn>1</mn>
                                    </mrow>
                                </mfenced>
                                <mo>⁢</mo>
                                <mi mathvariant="italic">c</mi>
                            </mrow>
                        </math>
                        </td>
              </tr>
              <tr>
                <td style="text-align: left; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <code class="constant">GL_SHORT</code>
                        </td>
                <td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <math overflow="scroll">
                            
                            <mrow>
                                <msup><mn>2</mn>
                                <mn>15</mn>
                                </msup>
                                <mo>-</mo>
                                <mn>1</mn>
                            </mrow>
                        </math>
                        </td>
                <td style="text-align: center; border-bottom: 2px solid ; ">
                        <math overflow="scroll">
                            
                            <mfrac>
                                <mfenced open="" close="">
                                    <mrow>
                                        <mfenced open="(" close=")">
                                            <mrow>
                                                <msup><mn>2</mn>
                                                <mn>16</mn>
                                                </msup>
                                                <mo>-</mo>
                                                <mn>1</mn>
                                            </mrow>
                                        </mfenced>
                                        <mo>⁢</mo>
                                        <mi mathvariant="italic">c</mi>
                                        <mo>-</mo>
                                        <mn>1</mn>
                                    </mrow>
                                </mfenced>
                                <mn>2</mn>
                            </mfrac>
                        </math>
                        </td>
              </tr>
              <tr>
                <td style="text-align: left; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <code class="constant">GL_UNSIGNED_INT</code>
                        </td>
                <td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <math overflow="scroll">
                            
                            <mrow>
                                <msup><mn>2</mn>
                                <mn>32</mn>
                                </msup>
                                <mo>-</mo>
                                <mn>1</mn>
                            </mrow>
                        </math>
                        </td>
                <td style="text-align: center; border-bottom: 2px solid ; ">
                        <math overflow="scroll">
                            
                            <mrow>
                                <mfenced open="(" close=")">
                                    <mrow>
                                        <msup><mn>2</mn>
                                        <mn>32</mn>
                                        </msup>
                                        <mo>-</mo>
                                        <mn>1</mn>
                                    </mrow>
                                </mfenced>
                                <mo>⁢</mo>
                                <mi mathvariant="italic">c</mi>
                            </mrow>
                        </math>
                        </td>
              </tr>
              <tr>
                <td style="text-align: left; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <code class="constant">GL_INT</code>
                        </td>
                <td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <math overflow="scroll">
                            
                            <mrow>
                                <msup><mn>2</mn>
                                <mn>31</mn>
                                </msup>
                                <mo>-</mo>
                                <mn>1</mn>
                            </mrow>
                        </math>
                        </td>
                <td style="text-align: center; border-bottom: 2px solid ; ">
                        <math overflow="scroll">
                            
                            <mfrac>
                                <mfenced open="" close="">
                                    <mrow>
                                        <mfenced open="(" close=")">
                                            <mrow>
                                                <msup><mn>2</mn>
                                                <mn>32</mn>
                                                </msup>
                                                <mo>-</mo>
                                                <mn>1</mn>
                                            </mrow>
                                        </mfenced>
                                        <mo>⁢</mo>
                                        <mi mathvariant="italic">c</mi>
                                        <mo>-</mo>
                                        <mn>1</mn>
                                    </mrow>
                                </mfenced>
                                <mn>2</mn>
                            </mfrac>
                        </math>
                        </td>
              </tr>
              <tr>
                <td style="text-align: left; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <code class="constant">GL_HALF_FLOAT</code>
                        </td>
                <td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        none
                        </td>
                <td style="text-align: center; border-bottom: 2px solid ; ">
                        <math overflow="scroll"><mi mathvariant="italic">c</mi></math>
                        </td>
              </tr>
              <tr>
                <td style="text-align: left; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <code class="constant">GL_FLOAT</code>
                        </td>
                <td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        none
                        </td>
                <td style="text-align: center; border-bottom: 2px solid ; ">
                        <math overflow="scroll"><mi mathvariant="italic">c</mi></math>
                        </td>
              </tr>
              <tr>
                <td style="text-align: left; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <code class="constant">GL_UNSIGNED_BYTE_3_3_2</code>
                        </td>
                <td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <math overflow="scroll">
                            
                            <mrow>
                                <msup><mn>2</mn>
                                <mn>N</mn>
                                </msup>
                                <mo>-</mo>
                                <mn>1</mn>
                            </mrow>
                        </math>
                        </td>
                <td style="text-align: center; border-bottom: 2px solid ; ">
                        <math overflow="scroll">
                            
                            <mrow>
                                <mfenced open="(" close=")">
                                    <mrow>
                                        <msup><mn>2</mn>
                                        <mn>N</mn>
                                        </msup>
                                        <mo>-</mo>
                                        <mn>1</mn>
                                    </mrow>
                                </mfenced>
                                <mo>⁢</mo>
                                <mi mathvariant="italic">c</mi>
                            </mrow>
                        </math>
                        </td>
              </tr>
              <tr>
                <td style="text-align: left; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <code class="constant">GL_UNSIGNED_BYTE_2_3_3_REV</code>
                        </td>
                <td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <math overflow="scroll">
                            
                            <mrow>
                                <msup><mn>2</mn>
                                <mn>N</mn>
                                </msup>
                                <mo>-</mo>
                                <mn>1</mn>
                            </mrow>
                        </math>
                        </td>
                <td style="text-align: center; border-bottom: 2px solid ; ">
                        <math overflow="scroll">
                            
                            <mrow>
                                <mfenced open="(" close=")">
                                    <mrow>
                                        <msup><mn>2</mn>
                                        <mn>N</mn>
                                        </msup>
                                        <mo>-</mo>
                                        <mn>1</mn>
                                    </mrow>
                                </mfenced>
                                <mo>⁢</mo>
                                <mi mathvariant="italic">c</mi>
                            </mrow>
                        </math>
                        </td>
              </tr>
              <tr>
                <td style="text-align: left; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <code class="constant">GL_UNSIGNED_SHORT_5_6_5</code>
                        </td>
                <td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <math overflow="scroll">
                            
                            <mrow>
                                <msup><mn>2</mn>
                                <mn>N</mn>
                                </msup>
                                <mo>-</mo>
                                <mn>1</mn>
                            </mrow>
                        </math>
                        </td>
                <td style="text-align: center; border-bottom: 2px solid ; ">
                        <math overflow="scroll">
                            
                            <mrow>
                                <mfenced open="(" close=")">
                                    <mrow>
                                        <msup><mn>2</mn>
                                        <mn>N</mn>
                                        </msup>
                                        <mo>-</mo>
                                        <mn>1</mn>
                                    </mrow>
                                </mfenced>
                                <mo>⁢</mo>
                                <mi mathvariant="italic">c</mi>
                            </mrow>
                        </math>
                        </td>
              </tr>
              <tr>
                <td style="text-align: left; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <code class="constant">GL_UNSIGNED_SHORT_5_6_5_REV</code>
                        </td>
                <td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <math overflow="scroll">
                            
                            <mrow>
                                <msup><mn>2</mn>
                                <mn>N</mn>
                                </msup>
                                <mo>-</mo>
                                <mn>1</mn>
                            </mrow>
                        </math>
                        </td>
                <td style="text-align: center; border-bottom: 2px solid ; ">
                        <math overflow="scroll">
                            
                            <mrow>
                                <mfenced open="(" close=")">
                                    <mrow>
                                        <msup><mn>2</mn>
                                        <mn>N</mn>
                                        </msup>
                                        <mo>-</mo>
                                        <mn>1</mn>
                                    </mrow>
                                </mfenced>
                                <mo>⁢</mo>
                                <mi mathvariant="italic">c</mi>
                            </mrow>
                        </math>
                        </td>
              </tr>
              <tr>
                <td style="text-align: left; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <code class="constant">GL_UNSIGNED_SHORT_4_4_4_4</code>
                        </td>
                <td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <math overflow="scroll">
                            
                            <mrow>
                                <msup><mn>2</mn>
                                <mn>N</mn>
                                </msup>
                                <mo>-</mo>
                                <mn>1</mn>
                            </mrow>
                        </math>
                        </td>
                <td style="text-align: center; border-bottom: 2px solid ; ">
                        <math overflow="scroll">
                            
                            <mrow>
                                <mfenced open="(" close=")">
                                    <mrow>
                                        <msup><mn>2</mn>
                                        <mn>N</mn>
                                        </msup>
                                        <mo>-</mo>
                                        <mn>1</mn>
                                    </mrow>
                                </mfenced>
                                <mo>⁢</mo>
                                <mi mathvariant="italic">c</mi>
                            </mrow>
                        </math>
                        </td>
              </tr>
              <tr>
                <td style="text-align: left; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <code class="constant">GL_UNSIGNED_SHORT_4_4_4_4_REV</code>
                        </td>
                <td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <math overflow="scroll">
                            
                            <mrow>
                                <msup><mn>2</mn>
                                <mn>N</mn>
                                </msup>
                                <mo>-</mo>
                                <mn>1</mn>
                            </mrow>
                        </math>
                        </td>
                <td style="text-align: center; border-bottom: 2px solid ; ">
                        <math overflow="scroll">
                            
                            <mrow>
                                <mfenced open="(" close=")">
                                    <mrow>
                                        <msup><mn>2</mn>
                                        <mn>N</mn>
                                        </msup>
                                        <mo>-</mo>
                                        <mn>1</mn>
                                    </mrow>
                                </mfenced>
                                <mo>⁢</mo>
                                <mi mathvariant="italic">c</mi>
                            </mrow>
                        </math>
                        </td>
              </tr>
              <tr>
                <td style="text-align: left; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <code class="constant">GL_UNSIGNED_SHORT_5_5_5_1</code>
                        </td>
                <td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <math overflow="scroll">
                            
                            <mrow>
                                <msup><mn>2</mn>
                                <mn>N</mn>
                                </msup>
                                <mo>-</mo>
                                <mn>1</mn>
                            </mrow>
                        </math>
                        </td>
                <td style="text-align: center; border-bottom: 2px solid ; ">
                        <math overflow="scroll">
                            
                            <mrow>
                                <mfenced open="(" close=")">
                                    <mrow>
                                        <msup><mn>2</mn>
                                        <mn>N</mn>
                                        </msup>
                                        <mo>-</mo>
                                        <mn>1</mn>
                                    </mrow>
                                </mfenced>
                                <mo>⁢</mo>
                                <mi mathvariant="italic">c</mi>
                            </mrow>
                        </math>
                        </td>
              </tr>
              <tr>
                <td style="text-align: left; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <code class="constant">GL_UNSIGNED_SHORT_1_5_5_5_REV</code>
                        </td>
                <td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <math overflow="scroll">
                            
                            <mrow>
                                <msup><mn>2</mn>
                                <mn>N</mn>
                                </msup>
                                <mo>-</mo>
                                <mn>1</mn>
                            </mrow>
                        </math>
                        </td>
                <td style="text-align: center; border-bottom: 2px solid ; ">
                        <math overflow="scroll">
                            
                            <mrow>
                                <mfenced open="(" close=")">
                                    <mrow>
                                        <msup><mn>2</mn>
                                        <mn>N</mn>
                                        </msup>
                                        <mo>-</mo>
                                        <mn>1</mn>
                                    </mrow>
                                </mfenced>
                                <mo>⁢</mo>
                                <mi mathvariant="italic">c</mi>
                            </mrow>
                        </math>
                        </td>
              </tr>
              <tr>
                <td style="text-align: left; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <code class="constant">GL_UNSIGNED_INT_8_8_8_8</code>
                        </td>
                <td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <math overflow="scroll">
                            
                            <mrow>
                                <msup><mn>2</mn>
                                <mn>N</mn>
                                </msup>
                                <mo>-</mo>
                                <mn>1</mn>
                            </mrow>
                        </math>
                        </td>
                <td style="text-align: center; border-bottom: 2px solid ; ">
                        <math overflow="scroll">
                            
                            <mrow>
                                <mfenced open="(" close=")">
                                    <mrow>
                                        <msup><mn>2</mn>
                                        <mn>N</mn>
                                        </msup>
                                        <mo>-</mo>
                                        <mn>1</mn>
                                    </mrow>
                                </mfenced>
                                <mo>⁢</mo>
                                <mi mathvariant="italic">c</mi>
                            </mrow>
                        </math>
                        </td>
              </tr>
              <tr>
                <td style="text-align: left; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <code class="constant">GL_UNSIGNED_INT_8_8_8_8_REV</code>
                        </td>
                <td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <math overflow="scroll">
                            
                            <mrow>
                                <msup><mn>2</mn>
                                <mn>N</mn>
                                </msup>
                                <mo>-</mo>
                                <mn>1</mn>
                            </mrow>
                        </math>
                        </td>
                <td style="text-align: center; border-bottom: 2px solid ; ">
                        <math overflow="scroll">
                            
                            <mrow>
                                <mfenced open="(" close=")">
                                    <mrow>
                                        <msup><mn>2</mn>
                                        <mn>N</mn>
                                        </msup>
                                        <mo>-</mo>
                                        <mn>1</mn>
                                    </mrow>
                                </mfenced>
                                <mo>⁢</mo>
                                <mi mathvariant="italic">c</mi>
                            </mrow>
                        </math>
                        </td>
              </tr>
              <tr>
                <td style="text-align: left; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <code class="constant">GL_UNSIGNED_INT_10_10_10_2</code>
                        </td>
                <td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <math overflow="scroll">
                            
                            <mrow>
                                <msup><mn>2</mn>
                                <mn>N</mn>
                                </msup>
                                <mo>-</mo>
                                <mn>1</mn>
                            </mrow>
                        </math>
                        </td>
                <td style="text-align: center; border-bottom: 2px solid ; ">
                        <math overflow="scroll">
                            
                            <mrow>
                                <mfenced open="(" close=")">
                                    <mrow>
                                        <msup><mn>2</mn>
                                        <mn>N</mn>
                                        </msup>
                                        <mo>-</mo>
                                        <mn>1</mn>
                                    </mrow>
                                </mfenced>
                                <mo>⁢</mo>
                                <mi mathvariant="italic">c</mi>
                            </mrow>
                        </math>
                        </td>
              </tr>
              <tr>
                <td style="text-align: left; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <code class="constant">GL_UNSIGNED_INT_2_10_10_10_REV</code>
                        </td>
                <td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <math overflow="scroll">
                            
                            <mrow>
                                <msup><mn>2</mn>
                                <mn>N</mn>
                                </msup>
                                <mo>-</mo>
                                <mn>1</mn>
                            </mrow>
                        </math>
                        </td>
                <td style="text-align: center; border-bottom: 2px solid ; ">
                        <math overflow="scroll">
                            
                            <mrow>
                                <mfenced open="(" close=")">
                                    <mrow>
                                        <msup><mn>2</mn>
                                        <mn>N</mn>
                                        </msup>
                                        <mo>-</mo>
                                        <mn>1</mn>
                                    </mrow>
                                </mfenced>
                                <mo>⁢</mo>
                                <mi mathvariant="italic">c</mi>
                            </mrow>
                        </math>
                        </td>
              </tr>
              <tr>
                <td style="text-align: left; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <code class="constant">GL_UNSIGNED_INT_24_8</code>
                        </td>
                <td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <math overflow="scroll">
                            
                            <mrow>
                                <msup><mn>2</mn>
                                <mn>N</mn>
                                </msup>
                                <mo>-</mo>
                                <mn>1</mn>
                            </mrow>
                        </math>
                        </td>
                <td style="text-align: center; border-bottom: 2px solid ; ">
                        <math overflow="scroll">
                            
                            <mrow>
                                <mfenced open="(" close=")">
                                    <mrow>
                                        <msup><mn>2</mn>
                                        <mn>N</mn>
                                        </msup>
                                        <mo>-</mo>
                                        <mn>1</mn>
                                    </mrow>
                                </mfenced>
                                <mo>⁢</mo>
                                <mi mathvariant="italic">c</mi>
                            </mrow>
                        </math>
                        </td>
              </tr>
              <tr>
                <td style="text-align: left; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <code class="constant">GL_UNSIGNED_INT_10F_11F_11F_REV</code>
                        </td>
                <td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        --
                        </td>
                <td style="text-align: center; border-bottom: 2px solid ; ">
                        Special
                        </td>
              </tr>
              <tr>
                <td style="text-align: left; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        <code class="constant">GL_UNSIGNED_INT_5_9_9_9_REV</code>
                        </td>
                <td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
                        --
                        </td>
                <td style="text-align: center; border-bottom: 2px solid ; ">
                        Special
                        </td>
              </tr>
              <tr>
                <td style="text-align: left; border-right: 2px solid ; ">
                        <code class="constant">GL_FLOAT_32_UNSIGNED_INT_24_8_REV</code>
                        </td>
                <td style="text-align: center; border-right: 2px solid ; ">
                        none
                        </td>
                <td style="text-align: center; ">
                        <math overflow="scroll"><mi mathvariant="italic">c</mi></math> (Depth Only)
                        </td>
              </tr>
            </tbody>
          </table>
        </div>
        <p>
            Return values are placed in memory as follows.
            If <em class="parameter"><code>format</code></em> is
            <code class="constant">GL_STENCIL_INDEX</code>,
            <code class="constant">GL_DEPTH_COMPONENT</code>,
            <code class="constant">GL_RED</code>,
            <code class="constant">GL_GREEN</code>, or
            <code class="constant">GL_BLUE</code>,
            a single value is returned and the data for the
            <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">i</mml:mi></mml:math>th
            pixel in the
            <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">j</mml:mi></mml:math>th
            row
            is placed in location
            <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
                
                <mml:mrow>
                    <mml:mfenced open="(" close=")">
                        <mml:mi mathvariant="italic">j</mml:mi>
                    </mml:mfenced>
                    <mml:mo>⁢</mml:mo>
                    <mml:mi mathvariant="italic">width</mml:mi>
                    <mml:mo>+</mml:mo>
                    <mml:mi mathvariant="italic">i</mml:mi>
                </mml:mrow>
            </mml:math>. <code class="constant">GL_RGB</code> and
    <code class="constant">GL_BGR</code> return three values,
    <code class="constant">GL_RGBA</code> and <code class="constant">GL_BGRA</code> return four
    values for each pixel, with all values corresponding to a single pixel
    occupying contiguous space in <em class="parameter"><code>data</code></em>. Storage
    parameters set by
    <a class="citerefentry" href="glPixelStore.xhtml"><span class="citerefentry"><span class="refentrytitle">glPixelStore</span></span></a>,
    such as <code class="constant">GL_PACK_LSB_FIRST</code> and
    <code class="constant">GL_PACK_SWAP_BYTES</code>, affect the way that data is
    written into memory. See
    <a class="citerefentry" href="glPixelStore.xhtml"><span class="citerefentry"><span class="refentrytitle">glPixelStore</span></span></a> for a description.</p>
        <p><code class="function">glReadnPixels</code> function will only handle the
    call if <em class="parameter"><code>bufSize</code></em> is at least of the size required to
    store the requested data. Otherwise, it will generate a
    <code class="constant">GL_INVALID_OPERATION</code> error.</p>
      </div>
      <div class="refsect1" id="notes">
        <h2>Notes</h2>
        <p>Values for pixels that lie outside the window connected to the
    current GL context are undefined.</p>
        <p>If an error is generated, no change is made to the contents of
    <em class="parameter"><code>data</code></em>.</p>
      </div>
      <div class="refsect1" id="errors">
        <h2>Errors</h2>
        <p><code class="constant">GL_INVALID_ENUM</code> is generated if
    <em class="parameter"><code>format</code></em> or <em class="parameter"><code>type</code></em> is not an
    accepted value.</p>
        <p><code class="constant">GL_INVALID_VALUE</code> is generated if either
    <em class="parameter"><code>width</code></em> or <em class="parameter"><code>height</code></em> is
    negative.</p>
        <p><code class="constant">GL_INVALID_OPERATION</code> is generated if
    <em class="parameter"><code>format</code></em> is <code class="constant">GL_STENCIL_INDEX</code> and
    there is no stencil buffer.</p>
        <p><code class="constant">GL_INVALID_OPERATION</code> is generated if
    <em class="parameter"><code>format</code></em> is <code class="constant">GL_DEPTH_COMPONENT</code>
    and there is no depth buffer.</p>
        <p><code class="constant">GL_INVALID_OPERATION</code> is generated if
    <em class="parameter"><code>format</code></em> is <code class="constant">GL_DEPTH_STENCIL</code> and
    there is no depth buffer or if there is no stencil buffer.</p>
        <p><code class="constant">GL_INVALID_ENUM</code> is generated if
    <em class="parameter"><code>format</code></em> is <code class="constant">GL_DEPTH_STENCIL</code> and
    <em class="parameter"><code>type</code></em> is not
    <code class="constant">GL_UNSIGNED_INT_24_8</code> or
    <code class="constant">GL_FLOAT_32_UNSIGNED_INT_24_8_REV</code>.</p>
        <p><code class="constant">GL_INVALID_OPERATION</code> is generated if
    <em class="parameter"><code>type</code></em> is one of
    <code class="constant">GL_UNSIGNED_BYTE_3_3_2</code>,
    <code class="constant">GL_UNSIGNED_BYTE_2_3_3_REV</code>,
    <code class="constant">GL_UNSIGNED_SHORT_5_6_5</code>, or
    <code class="constant">GL_UNSIGNED_SHORT_5_6_5_REV</code> and
    <em class="parameter"><code>format</code></em> is not <code class="constant">GL_RGB</code>.</p>
        <p><code class="constant">GL_INVALID_OPERATION</code> is generated if
    <em class="parameter"><code>type</code></em> is one of
    <code class="constant">GL_UNSIGNED_SHORT_4_4_4_4</code>,
    <code class="constant">GL_UNSIGNED_SHORT_4_4_4_4_REV</code>,
    <code class="constant">GL_UNSIGNED_SHORT_5_5_5_1</code>,
    <code class="constant">GL_UNSIGNED_SHORT_1_5_5_5_REV</code>,
    <code class="constant">GL_UNSIGNED_INT_8_8_8_8</code>,
    <code class="constant">GL_UNSIGNED_INT_8_8_8_8_REV</code>,
    <code class="constant">GL_UNSIGNED_INT_10_10_10_2</code>, or
    <code class="constant">GL_UNSIGNED_INT_2_10_10_10_REV</code> and
    <em class="parameter"><code>format</code></em> is neither <code class="constant">GL_RGBA</code> nor
    <code class="constant">GL_BGRA</code>.</p>
        <p><code class="constant">GL_INVALID_OPERATION</code> is generated if a non-zero
    buffer object name is bound to the
    <code class="constant">GL_PIXEL_PACK_BUFFER</code> target and the buffer object's
    data store is currently mapped.</p>
        <p><code class="constant">GL_INVALID_OPERATION</code> is generated if a non-zero
    buffer object name is bound to the
    <code class="constant">GL_PIXEL_PACK_BUFFER</code> target and the data would be
    packed to the buffer object such that the memory writes required would
    exceed the data store size.</p>
        <p><code class="constant">GL_INVALID_OPERATION</code> is generated if a non-zero
    buffer object name is bound to the
    <code class="constant">GL_PIXEL_PACK_BUFFER</code> target and
    <em class="parameter"><code>data</code></em> is not evenly divisible into the number of
    bytes needed to store in memory a datum indicated by
    <em class="parameter"><code>type</code></em>.</p>
        <p><code class="constant">GL_INVALID_OPERATION</code> is generated if
    <code class="constant">GL_READ_FRAMEBUFFER_BINDING</code> is non-zero, the read
    framebuffer is complete, and the value of
    <code class="constant">GL_SAMPLE_BUFFERS</code> for the read framebuffer is greater
    than zero.</p>
        <p><code class="constant">GL_INVALID_OPERATION</code> is generated by
    <code class="function">glReadnPixels</code> if the buffer size required to store
    the requested data is greater than <em class="parameter"><code>bufSize</code></em>.</p>
      </div>
      <div class="refsect1" id="associatedgets">
        <h2>Associated Gets</h2>
        <p><a class="citerefentry" href="glGet.xhtml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a>
        with argument <code class="constant">GL_PIXEL_PACK_BUFFER_BINDING</code>
    </p>
      </div>
      <div class="refsect1" id="versions">
        <h2>Version Support</h2>
        <div class="informaltable">
          <table style="border-collapse: collapse; border-top: 2px solid ; border-bottom: 2px solid ; border-left: 2px solid ; border-right: 2px solid ; ">
            <colgroup>
              <col style="text-align: left; "/>
              <col style="text-align: center; " class="firstvers"/>
              <col style="text-align: center; "/>
              <col style="text-align: center; "/>
              <col style="text-align: center; "/>
              <col style="text-align: center; "/>
              <col style="text-align: center; "/>
              <col style="text-align: center; "/>
              <col style="text-align: center; "/>
              <col style="text-align: center; "/>
              <col style="text-align: center; "/>
              <col style="text-align: center; "/>
              <col style="text-align: center; " class="lastvers"/>
            </colgroup>
            <thead>
              <tr>
                <th style="text-align: left; border-right: 2px solid ; ">
                 
            </th>
                <th style="text-align: center; border-bottom: 2px solid ; " colspan="12">
                <span class="bold"><strong>OpenGL Version</strong></span>
            </th>
              </tr>
              <tr>
                <th style="text-align: left; border-right: 2px solid ; border-bottom: 2px solid ; ">
                <span class="bold"><strong>Function / Feature Name</strong></span>
            </th>
                <th style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
                <span class="bold"><strong>2.0</strong></span>
            </th>
                <th style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
                <span class="bold"><strong>2.1</strong></span>
            </th>
                <th style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
                <span class="bold"><strong>3.0</strong></span>
            </th>
                <th style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
                <span class="bold"><strong>3.1</strong></span>
            </th>
                <th style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
                <span class="bold"><strong>3.2</strong></span>
            </th>
                <th style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
                <span class="bold"><strong>3.3</strong></span>
            </th>
                <th style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
                <span class="bold"><strong>4.0</strong></span>
            </th>
                <th style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
                <span class="bold"><strong>4.1</strong></span>
            </th>
                <th style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
                <span class="bold"><strong>4.2</strong></span>
            </th>
                <th style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
                <span class="bold"><strong>4.3</strong></span>
            </th>
                <th style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
                <span class="bold"><strong>4.4</strong></span>
            </th>
                <th style="text-align: center; border-bottom: 2px solid ; ">
                <span class="bold"><strong>4.5</strong></span>
            </th>
              </tr>
            </thead>
            <tbody>
              <tr>
                <td style="text-align: left; border-right: 2px solid ; border-bottom: 2px solid ; ">
                  <code class="function">glReadPixels</code>
                </td>
                <td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">✔</td>
                <td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">✔</td>
                <td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">✔</td>
                <td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">✔</td>
                <td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">✔</td>
                <td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">✔</td>
                <td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">✔</td>
                <td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">✔</td>
                <td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">✔</td>
                <td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">✔</td>
                <td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">✔</td>
                <td style="text-align: center; border-bottom: 2px solid ; ">✔</td>
              </tr>
              <tr>
                <td style="text-align: left; border-right: 2px solid ; ">
                  <code class="function">glReadnPixels</code>
                </td>
                <td style="text-align: center; border-right: 2px solid ; ">-</td>
                <td style="text-align: center; border-right: 2px solid ; ">-</td>
                <td style="text-align: center; border-right: 2px solid ; ">-</td>
                <td style="text-align: center; border-right: 2px solid ; ">-</td>
                <td style="text-align: center; border-right: 2px solid ; ">-</td>
                <td style="text-align: center; border-right: 2px solid ; ">-</td>
                <td style="text-align: center; border-right: 2px solid ; ">-</td>
                <td style="text-align: center; border-right: 2px solid ; ">-</td>
                <td style="text-align: center; border-right: 2px solid ; ">-</td>
                <td style="text-align: center; border-right: 2px solid ; ">-</td>
                <td style="text-align: center; border-right: 2px solid ; ">-</td>
                <td style="text-align: center; ">✔</td>
              </tr>
            </tbody>
          </table>
        </div>
      </div>
      <div class="refsect1" id="seealso">
        <h2>See Also</h2>
        <p>
            <a class="citerefentry" href="glPixelStore.xhtml"><span class="citerefentry"><span class="refentrytitle">glPixelStore</span></span></a>,
            <a class="citerefentry" href="glReadBuffer.xhtml"><span class="citerefentry"><span class="refentrytitle">glReadBuffer</span></span></a>
        </p>
      </div>
      <div class="refsect1" id="Copyright">
        <h2>Copyright</h2>
        <p>
            Copyright <span class="trademark"/>© 1991-2006 Silicon Graphics, Inc.
            Copyright <span class="trademark"/>© 2010-2014 Khronos Group.
            This document is licensed under the SGI Free Software B License.
            For details, see
            <a class="link" href="http://oss.sgi.com/projects/FreeB/" target="_top">http://oss.sgi.com/projects/FreeB/</a>.
        </p>
      </div>
    </div>
    <footer/>
  </body>
</html>
